Developing-tank for photographic films.



A. C. HAYDEN. DEVELOPING TANK FOR PHOTOGRAPHIG FILMS. APPLICATION FILED JAN.6,1910.

978, 156. Patented Dec. 13, 1910.

ARTHUR C. HAYDEN, OF BROCKTON, MASSACHUSETTS.

DEVELOPING-TANK FOR PHOTOGRAPHIC FILMS.

Specification of Letters Patent.

Patented Dec. 13, 1910.

Application filed January 6, 1910. Serial No. 536,606.

To all whom it may concern:

Be it known that I, ARTHUR G. HAYDEN, a citizen of the United States, residing at Brockton, in the county of Plymouth and State of Massachusetts, have invented a new and useful Developing Tank for Photographic Films, of which the following is a specification.

This invention has reference to improvements in developing tanks for photographic films whereby the film may be treated to a developing bath and to such other baths as may be desired. without the necessity of using a dark room.

In accordance with the present invention the spool upon which the film is wound after exposure in a camera is introduced into the developing machine without other manipulation and then while the receptacle or tank for the developing fluid is rendered actinically light tight by a suitable cover the film is unwound from the spool and by a progressive movement of the mechanism causing the unwinding of the film it may be rewound in the reverse direction upon the same spool to be again unwound by a reversal of direction of rotation of the spool and once more rewound thereon in the first direction, and this operation may be repeated as often as necessary to cause the development of the film, the invention contemplating means for supporting the film during the unwinding and rewinding operation, the film still remaining attached to the spool upon which it was wound in the camera after having been exposed in the usual manner.

The invention will be best understood from a consideration of the following detail description taken in connection with the accompanying drawings forming a part of this specification, in. which drawings,

Figure 1 is a longitudinal central. section of a developing tank constructed in accordance with the present invention. Fig. l is a section on the line A-B of Fig. 1.

Referring to the drawings there is shown a tank 1 which may be in the form of a cylinder or may be otherwise shaped as desired and this tank is usually made of metal suitably protected against the action of developing and fixing solutions by nickel plating or otherwise. The tank is open at one end and there receives a cover 2 having a peripheral flange 3 so shaped as to embrace the open end of the tank 1 sufiiciently close to exclude light and to prevent any liquidintroduced into the tank from spilling therefrom although such a tight fit is not mandatory.

Near the open end of the tank there is formed a passage 4: through the wall of the tank and through the flange 3 there is a pas sage 5 and these passages may be brought into matching relation by suitably turning the cover 2, or the passages may be moved out of alinement by a suitable turning of the cover 2 on the tank 1.

Secured to the inner surface of the cover 2 there is a diametrically disposed strap 6 having a central portion 7 parallel with but spaced from the inner face of the cover and held to the cover by the ends of the strap which are appropriately bent for the purpose. One end of the strap 6 may be secured'to the cover 2 by a simple rivet while the other end of the strap 6 may be secured to the cover 2 by one end of a rod 8 having the end passing through the strap 6 riveted to the cover while the other end extends into the tank when the cover is applied thereto to a point near the bottom 01 the tank, the rod being substantially parallel with and close to the side wall of the tank.

Extending axially through the cover is an arbor 9 free to rotate on its longitudinal axis but held against movement in the direction of the length of its longitudinal axis by washers 10 applied to the arbor on opposite sides of the cover 2. Exterior to the cover the arbor is bent into a crank 11 while interior to the cover the arbor 9 extends through a suitable bearing formed in the central portion 7 of the strap 6 and beyond this central portion the arbor is formed into or has secured thereto a short taper screw 12.

There are provided two disks 13, let, each of these disks having a central boss 15 which in turn is centrally perforated, the boss being formed by upsetting the metal of the disk. Each disk is formed with a circular series of perforations 16 near the periphery. There is also provided a thumb screw 17 the purpose of which will presently appear and clips 18 adapted to the rod 8 are also provided.

In the drawings there is shown a spool 19 of the ordinary type employed in cameras using sensitized films as the photo-sensitive medium and while no attempt is made to show the film and its protecting paper strip, it will be understood that the spool 19 is assumed to have thereon a film of usual length with the usual black paper strip interwound therewith. parts for causing the development of the exposed film the cover 2 is removed from the tank and the disk 13 is threadct on the rod which latter passes through one of the circular series of perforations 16 while the screw 12 is caused to pass through the central perforation about which the boss 15 is formed. Then the spool 19 is screwed upon the screw 12 entering one of the axial holes in the end of the spool, the proper end being indicated by a cross cut usually present in such spools. The other disk 11 is now threaded on the rod 8 by means of one of the perforations 16 and then the thumb screw 17 is passed through the plate 11 and screwed into the corresponding end of the spool 19, care being taken to prevent binding of the parts since the disks 13 and 14 do not rotate in the operation of the device. The outer end of the black paper covering on the spool is now unwound sulliciently to be passed around the rod 8 and then one or more of the clips 18 are used to secure the end of the paper to the rod 8. The tank 1 is filled to the proper height, which height may be indicated by one of a series of stiffening beads 20 .in the body of the tank, with a suitable developing solution. and then the cover 2 is applied to the tank with the spool 19 and the film carried thereby immersed in the solution within the tank, care being taken that the passages a and 5 are not now in alinement so that no light will reach the interior of the tank. Now by turning the crank 11 in a direction to cause the unwinding of the film and paper covering from the spool 19 the film is loosened up and the turns of the film are separated so that the sensitive surface is readily reached by the developing solution. By continuing the rotation of the crank 1.1 in the same direction the film becomes entirely unwound from the body of the spool and is then rewound in the reversed direction thereon until the rotative movement of the crank is stopped because the end of the black paper covering is secured to the rod 8. The direction of rotation of the crank 11 may now be reversed and the film be again unwound from the spool and rewound thereon in the original direction and this operation may be repeated a suitable number of times until the full time for development has elapsed. The disks 13 and 14 serve as expanded heads for the spool and support the film and paper covering against sagging during the unwinding and rewinding operations. On the completion of the development the passages 4 and 5 are brought into alinement and then the developing fluid may be poured from the tank without removing the cover and washing water may be introduced into the tank through these passages and the film In assembling the may be unwound and rewound in the manner before described until any clinging developer has been washed from the film. For fixing the film the wash water may be poured from the tank and a suit-able fixing bath introduced through the passages 4t and and the washed film may be removed from the tank and unwound and fixed in the usual manner of open tank fixing. The entire operation of developing, fixing and washing may take place within the tank 1. or the developing only and the washing of the developer from the film may be performed while the film is in the tank, the succeeding operations being performed on the film after removal from the tank.

It will be observed that the film spool is carried entirely by the arbor f) engaging one end only of the spool while the disk 11 serves to center the spool against excessive 'abbling or prevent decentering of the spool as might occur from the pull of the black paper when the film and paper become fully wound on the spool after being unwound therefrom.

It will be observed that the developing tank will take spools of different lengths up to the maximum lengths of spool for which a, tank may be designed.

It will be evident of course that the head 13 may be made fast to the central portion of the strap (3 instead of being simply c011- fined against the latter by the spool 19 when screwed upon the arbor.

hat is claimed is 1. In an apparatus of the class described, a suitable tank, a removable cover therefor, an arbor carried by the cover and extending beyond the inner face of the latter, said arbor being provided at its inner end with means for the attachment thereto and suspension thereby of the spool on which the film is carried in a camera, a head for the end of the spool remote from that carried by the arbor and of greater diameter than the diameter of the normal head of the spool, and means for the ready attachment of the su 'iplemental head to the spool.

2. In an apparatus of the class described, a tank, a cover therefor, an arbor extending through the cover and having spaced bearings carried by the cover, one of the bearings being interior to the tank when the cover is applied, and said arbor having means at its inner end for attachment to and suspension of a film spool, a rod carried by the cover at one side of and parallel with the axis of the arbor and provided with means for holding the free end of the protecting envelop of the film, and supplemental heads for the film spool attachable to and removable therefrom.

In an apparatus of the class described, a suitable tank, a removable cover therefor, an arbor carried by the cover and extending beyond the inner face of the latter and there provided with means for the attachment and suspension of the spool on which the film is carried in a camera, and a supplemental head for the spool for upholding the film within the tank when unwound from the spool.

4C. In an apparatus of the class described, a suitable receptacle, an arbor entering the same and provided at the inner end with screw threads adapted to engage a film spool within the receptacle and constituting the sole means of supporting said spool, a rod within the receptacle when the latter is in operative condition and then in fixed relation to the receptacle, said rod constituting means for holding one end of the protecting envelop of the film and a supplemental head for the end of the spool remote from that engaged by the arbor, said head having means for the ready attachment thereof to the spool, and also engaging the rod.

5. In an apparatus of the class described, a suitable tank, a removable cover therefor,

an arbor carried by the cover and extending beyond the inner face of the latter, said arbor being provided at its inner end with means for the attachment and suspension of a spool on which the film is carried. in a camera, a rod carried by the cover to one side of and parallel with the longitudinal axis of the arbor, disks constituting supplemental heads for the film spool and each provided with a circular series of perforations any one of which is adapted to be traversed by the rod, one of said heads when in operation being carried by the arbor, and means for the attachment of the other head to the end of the spool remote from that engaged by the arbor.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

ARTHUR C. HAYDEN. 

